JP5819410B2 - Fiber, non-woven fabric and its use - Google Patents

Description

  The present invention relates to a fiber suitable for a top sheet of sanitary materials such as disposable diapers and sanitary products, in which growth of harmful bacteria is suppressed and skin irritation is reduced, and a nonwoven fabric including such a fiber.

  Nonwoven fabrics obtained from olefin polymers typified by polypropylene are widely used in various applications including sanitary materials because of their excellent breathability, flexibility and lightness. For this reason, the nonwoven fabric is required to have various properties according to its use and to improve the properties.

  For example, when used as a sanitary material such as paper diapers, it has skin-friendly flexibility, absorbability to quickly transfer urine, breathability to prevent stuffiness, antibacterial properties to prevent skin irritation caused by bacteria, etc. Required for non-woven fabrics. In particular, since skin irritation is a heavy burden on users, various methods for suppressing the generation of bacteria and malodors that cause irritation have been studied. Especially in recent years, since the skin is weakly acidic, by making the skin environment weakly acidic, it helps the growth of bacteria beneficial to the skin, and as a result, the growth of bacteria harmful to the skin is suppressed, resulting in skin irritation from bacteria. It has become clear that can be reduced.

  For example, Japanese translations of PCT publication No. 2003-516778 (patent document 1) discloses a method of impregnating a non-woven fabric with a pH control material made of citric acid or sodium citrate to maintain a pH environment comparable to the pH of the contacting skin. Has been. However, since citric acid described in Patent Document 1 is water-soluble, once it comes into contact with urine, a pH control material such as citric acid flows out and moves toward the absorber. It is difficult. Further, for example, Japanese Patent Application Laid-Open No. 2004-176225 (Patent Document 2) discloses a fiber treatment agent comprising a betaine amphoteric compound, an alkylene oxide addition type nonionic surfactant and / or an anionic surfactant such as a carboxylate. A method using a deodorant fiber to which is attached is disclosed. However, since the fiber treatment agent described in Patent Document 2 is attached to the fibers by coating, once the fiber treatment agent comes into contact with urine, the fiber treatment agent partially flows out and moves toward the absorbent body. Similar to 1, it is not satisfactory in terms of maintaining the effect.

  On the other hand, for example, Japanese Patent Publication No. 2005-530857 (Patent Document 3) discloses a method using an antibacterial composition containing an antibacterial active substance and an anionic surfactant. Various methods such as a method using a skin care composition containing a proton-donating active ingredient have been proposed. However, any method has a problem that the effect is reduced with time. In addition, in the method using an antibacterial composition, the growth of bacteria can be temporarily reduced by the action of an antibacterial agent, but the growth of beneficial bacteria together with harmful bacteria is also suppressed. It will be. Therefore, in the prior art, the effect of suppressing skin irritation that occurs when a diaper is worn is insufficient, and further improvement is required.

Special table 2003-516778 gazette JP 2004-176225 A JP 2005-530857 A Japanese translation of PCT publication No. 2002-505918

  The present inventors include a fiber suitable for a top sheet of a sanitary material such as a disposable diaper, a sanitary product, or a second sheet in which the growth of harmful bacteria is suppressed and the suppression of skin irritation can be sustained. As a result of studies conducted for the purpose of developing a nonwoven fabric, it has been found that a fiber obtained from an olefin polymer composition containing an anionic surfactant in an acid form, and a nonwoven fabric containing such a fiber can achieve the object. It was.

  The present invention is a fiber comprising an olefin polymer composition containing 0.1 to 30 parts by weight of an anionic surfactant in an acid form with respect to 100 parts by weight of an olefin polymer, the anion in the acid form The system surfactant provides a fiber obtained by melt-kneading the fiber.

  When used as a sanitary material such as diapers, the fiber according to the present invention and the nonwoven fabric containing the fiber are characterized in that the growth of harmful bacteria is suppressed and the sustainability of the skin irritation suppression effect is high.

<Olefin polymer>
The olefin polymer forming the fiber of the present invention and the nonwoven fabric containing the fiber is an α-olefin such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene alone or Specifically, high pressure method low density polyethylene, linear low density polyethylene (so-called LLDPE), high density polyethylene, ethylene / propylene random copolymer, ethylene / 1-butene random copolymer, etc. Ethylene polymers such as ethylene homopolymers or ethylene / α-olefin copolymers; propylene homopolymers (so-called polypropylene), propylene / ethylene random copolymers, propylene / ethylene / 1-butene random copolymers (So-called random polypropylene), propylene block copolymer, propylene Propylene polymers such as 1-butene random copolymer; 1-butene polymers such as 1-butene homopolymer, 1-butene / ethylene copolymer, 1-butene / propylene copolymer; poly-4- And methyl-1-pentene.

  Among these olefin polymers, a propylene polymer is preferable because a nonwoven fabric excellent in spinning stability during molding, processability and breathability of the nonwoven fabric, flexibility, light weight, and heat resistance can be obtained.

  In the olefin polymer according to the present invention, an auxiliary agent that promotes or suppresses hydrophilicity within a range that does not impair the object of the present invention, a commonly used antioxidant, weathering stabilizer, light stabilizer, antiblocking agent, Additives such as a lubricant, a nucleating agent, a pigment, a softening agent, a water repellent, a filler, an antibacterial agent, or a polymer other than an olefin polymer can be blended as necessary.

<Propylene polymer>
The propylene polymer according to the present invention is usually a propylene homopolymer having a melting point (Tm) of 125 ° C. or higher, preferably 130 to 165 ° C., or a small amount of ethylene, 1-butene, 1- One or two of 2 or more carbon atoms (excluding 3 carbon atoms), preferably 2-8 (excluding 3 carbon atoms) such as pentene, 1-hexene, 1-octene, 4-methyl-1-pentene Copolymers with more than one α-olefin are preferred.

  As long as the propylene polymer according to the present invention can be melt-spun, the melt flow rate (MFR: ASTM D-1238, 230 ° C., load 2160 g) is not particularly limited, but is usually 1 to 1000 g / 10 minutes, preferably It is in the range of 5 to 500 g / 10 minutes, more preferably 10 to 100 g / 10 minutes.

  Among the propylene polymers according to the present invention, propylene and a small amount of ethylene, 1-butene, 1-pentene, 1-hexene, having a melting point (Tm) in the range of 125 to 155 ° C, preferably 130 to 147 ° C, -Propylene / α-olefin random copolymer with 2 or more carbon atoms, preferably 2 to 8 or more α-olefins such as octene and 4-methyl-1-pentene is flexible, initial This is particularly preferable because a nonwoven fabric having excellent hydrophilicity can be obtained.

  The α-olefin content in the propylene / α-olefin random copolymer is not particularly limited as long as the melting point (Tm) is in the above range, but is usually in the range of 1 to 10 mol%. More preferably, it is 1-5 mol%.

<Anionic surfactant in acid form>
The anionic surfactant in the acid form according to the present invention is an anionic surfactant that can exhibit acidity in the presence of water or moisture. As the acid form anionic surfactant, an acid form anionic surfactant exhibiting weak acidity is preferable because it can express the ability to alleviate the change in pH by having a buffering ability. , Fatty acid or acid form phosphate ester type surfactants are preferred. Moreover, if it is the said surfactant of an acid form, it may be a partially neutralized salt like a monoalkyl phosphate ester salt which is not a completely neutralized salt.

  The anionic surfactant in the acid form according to the present invention is preferably 9 from the viewpoint of usually having a hydrophobic group having 8 or more carbon atoms, better melt-kneading properties, and stable operability during extrusion molding. More preferably, an anionic surfactant having an aliphatic hydrocarbon group having 12 or more, more preferably 13 or more, particularly preferably an anionic interface having an aliphatic hydrocarbon group having 18 to 28 carbon atoms. An activator or, preferably, a fatty acid having 9 or more carbon atoms, preferably 12 or more carbon atoms, more preferably 13 or more carbon atoms, particularly preferably 18 to 28 carbon atoms, or Preferably, the phosphoric acid ester type surfactant has 9 or more carbon atoms in the hydrophobic group, more preferably 12 or more, more preferably 13 or more, particularly preferably the hydrophobic group has 12 or more carbon atoms. Ku is a phosphate ester type surfactant in the range of 18-28. Phosphate-type surfactants include alkyl phosphate esters that are esters of aliphatic alcohols and phosphoric acid, alkyl ether phosphate esters that are esters of aliphatic alcohol alkylene oxide adducts and phosphoric acid, aromatics Examples thereof include alkylphenyl ether phosphates which are esters of an alkylene oxide adduct of alcohol and phosphoric acid.

  Further, the acid form anionic surfactant according to the present invention may be a mixture thereof. For example, a fatty acid having 18 to 28 carbon atoms, or a phosphoric acid ester type surfactant in an acid form is an alkyl phosphate ester or carbon that is an ester of an aliphatic alcohol having 18 to 28 carbon atoms and phosphoric acid. Alkyl ether phosphoric acid ester which is ester of alkylene oxide adduct of aliphatic alcohol having 18 to 28 and phosphoric acid, or ester of alkylene oxide adduct of aromatic alcohol having 18 to 28 carbon and phosphoric acid In the case of alkyl phenyl ether phosphate ester, or a mixture thereof. In the case of a fatty acid having 9 or more carbon atoms, a phosphate ester type surfactant having 9 or more carbon atoms, or a mixture thereof, a better melt kneadability can be obtained, and It is preferable because the anionic surfactant is suppressed from being eluted from the nonwoven fabric, and the durability of the effect can be obtained.

  Specific examples of the fatty acid according to the present invention include saturated fatty acids such as myristic acid, palmitic acid, stearic acid, and montanic acid, and unsaturated fatty acids such as oleic acid, linolenic acid, and nervonic acid.

  As the phosphate ester type surfactant in the acid form according to the present invention, as specific examples of alkyl phosphate esters, for example, monostearyl phosphate ester, distearyl phosphate ester, monobehenyl phosphate ester, dibehenyl phosphate ester, Monocetyl phosphate ester, dicetyl phosphate ester, monolauryl phosphate ester, dilauryl phosphate ester, monooctyl phosphate ester, dioctyl phosphate ester and the like, and specific examples of alkyl ether phosphate ester include, for example, mono (polyoxyethylene・ Stearyl ether) phosphate ester, di (polyoxyethylene stearyl ether) phosphate ester, mono (polyoxyethylene lauryl ether) phosphate ester, di (polyoxyethylene lauryl ether) phosphorus Examples of the alkyl phenyl ether phosphate ester include mono (polyoxyethylene / stearyl phenyl ether) phosphate, di (polyoxyethylene / stearyl phenyl ether) phosphate, mono (poly And oxyethylene / lauryl phenyl ether) phosphate, di (polyoxyethylene / lauryl phenyl ether) phosphate, and the like.

  Among these acid-form anionic surfactants, acid-form phosphate surfactants are particularly preferable.

<Nonionic surfactant>
As the nonionic surfactant according to the present invention, various known nonionic surfactants can be used, and the surface of the fiber exhibits hydrophilicity when added to form a fiber. If it does not specifically limit. Specific examples of nonionic surfactants include fatty acid glycerides, alkoxylated alkylphenols, polyoxyalkylene fatty acid esters, alkyl polyoxyethylene alcohols, fatty acid amides, polyoxyalkylene sorbitan fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, fatty acids Examples include alkanolamides, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, alkyl polyglucosides, fatty acid diethanolamides, and alkyl monoglyceryl ethers.

<Olefin polymer composition>
The olefin polymer composition according to the present invention is 0.1 to 30 parts by weight, preferably 1 to 15 parts by weight of the anionic surfactant in the acid form with respect to 100 parts by weight of the olefin polymer. More preferably, the composition contains 1.5 to 10 parts by weight.

  If the amount of the anionic surfactant in the acid form is less than 0.1 parts by weight, the effect of making the environment around the fiber weakly acidic is low. As a result, the nonwoven fabric using the fiber is used as a sanitary material such as sanitary goods and diapers. When used, the rash reduction effect may be insufficient. On the other hand, the upper limit of the addition amount is not particularly limited, but if it exceeds 30 parts by weight, the effect of weakening the environment around the fiber is saturated, and the acid that exudes to the surface of the resulting fiber and the nonwoven fabric containing the fiber is saturated. The amount of the anionic surfactant in the form increases, and the molding processability decreases.

  In addition to the acid form anionic surfactant, the olefin polymer composition according to the present invention may further include 0.1 to 30 parts of the nonionic surfactant with respect to 100 parts by weight of the olefin polymer. By including in the range of 0.5 parts by weight, preferably 0.5 to 15 parts by weight, the hydrophilicity of the resulting fiber can be improved, and a sudden change in pH due to the acid form anionic surfactant can be mitigated. .

  When preparing the olefin polymer composition according to the present invention, the anionic surfactant in the acid form is more than 5% by weight, for example, as a pellet-shaped masterbatch containing 10 to 40% by weight in a high concentration. It is preferable to add an anionic surfactant in the acid form and to mix with the olefin polymer at the time of producing fibers and nonwoven fabrics. The olefin polymer used in the master batch of the mixture with the anionic surfactant in the acid form is not limited to the olefin polymer, and other olefin polymers may be used. As the olefin polymer used in such a master batch, MFR can be appropriately selected according to the target fiber and the nonwoven fabric containing the fiber.

  In the olefin polymer composition according to the present invention, an antioxidant, a weather stabilizer, a light stabilizer, an antiblocking agent, a lubricant, a nucleating agent, a pigment, and the like that are usually used within a range not impairing the object of the present invention. Polymers other than additives or olefin polymers can be blended as required.

<Fiber and non-woven fabric>
The fiber of the present invention and the nonwoven fabric containing the fiber include the fiber of the olefin polymer composition containing the olefin polymer and the anionic surfactant in the acid form, and preferably the nonionic surfactant, and the fiber. It is a nonwoven fabric containing.

  In particular, when the acid form anionic surfactant is melted and kneaded with the olefin polymer, the effect of reducing skin irritation is preferred. Further, when the nonionic surfactant is used in combination, melt kneading is improved by melt kneading together with the acid form anionic surfactant, and the nonionic surfactant and the acid form of the acid form are improved. An anionic surfactant can be uniformly dispersed on the fiber surface.

  The fibers of the present invention usually have a fineness in the range of 0.5 to 5 denier. Although the fiber of the present invention may be a short fiber, it is preferable that the fiber is a long fiber because the fiber does not fall off from the resulting nonwoven fabric.

  The cross-sectional shape of the fiber of the present invention may be an irregular cross-section such as a V shape, a cross shape, or a T shape in addition to a round shape.

  The fiber of the present invention may be a crimped fiber made of an olefin polymer composition having at least two components of side-by-side type. Preferably, examples of the olefin polymer include side-by-side crimped fibers made of a propylene homopolymer and a propylene / ethylene random copolymer.

  In addition, the fiber of the present invention may be a concentric or eccentric fiber, and in that case, the acid form anionic surfactant may be provided in both or either of the core part and the sheath part. And preferably, the nonionic surfactant may be added.

  Furthermore, the fiber of the present invention may be a mixed nonwoven fabric with other fibers. For example, the fibers of the present invention may be a mixed nonwoven fabric of such crimped fibers and other non-crimped fibers.

The nonwoven fabric of the present invention usually has a basis weight of 10 to 30 g / m ² , preferably 15 to 25 g / m ² .

  The nonwoven fabric of the present invention is partially used by various known entanglement methods, for example, a method using means such as needle punching, water jet, and ultrasonic waves, or hot embossing using an embossing roll or hot air through. It may be entangled by a method of heat fusion. Such entanglement methods may be used alone or in combination with a plurality of entanglement methods.

  When heat-sealing by hot embossing, the embossed area ratio is usually in the range of 3 to 30%, preferably 5 to 20%. Examples of the stamped shape include a circle, an ellipse, an ellipse, a square, a rhombus, a rectangle, a square, a quilt, a lattice, a turtle shell, and a continuous shape based on these shapes.

  The nonwoven fabric of the present invention may be used alone or laminated with other layers depending on various applications.

  Specifically, the other layer laminated | stacked with the nonwoven fabric of this invention can mention a knitted fabric, a woven fabric, a nonwoven fabric, a film, a paper product etc., for example. When laminating (bonding) the nonwoven fabric of the present invention and other layers, thermal embossing, thermal fusion methods such as ultrasonic fusion, mechanical entanglement methods such as needle punch and water jet, hot melt adhesive, Various known methods such as a method using an adhesive such as a urethane-based adhesive, extrusion lamination, and the like can be adopted. The nonwoven fabric of the present invention is highly convenient in terms of product quality control because the rash reduction effect continues even after a process of contacting with a high-temperature substance such as a hot melt adhesive or an extrusion laminate.

  Examples of the nonwoven fabric laminated with the nonwoven fabric of the present invention include other known nonwoven fabrics such as other spunbond nonwoven fabrics, melt blown nonwoven fabrics, wet nonwoven fabrics, dry nonwoven fabrics, dry pulp nonwoven fabrics, flash spun nonwoven fabrics, and spread nonwoven fabrics.

  Examples of the material constituting such a nonwoven fabric include various known thermoplastic resins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene and other α-olefins. High pressure low density polyethylene, linear low density polyethylene (so-called LLDPE), high density polyethylene, polypropylene, polypropylene random copolymer, poly 1-butene, poly 4-methyl-1-pentene, ethylene / propylene random Polyolefin such as copolymer, ethylene / 1-butene random copolymer, propylene / 1-butene random copolymer, polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon- 66, polymer Xylene adipamide, etc.), polyvinyl chloride, polyimide, ethylene-vinyl acetate copolymer, polyacrylonitrile, polycarbonate can be exemplified polystyrene, ionomers, thermoplastic polyurethane, or mixtures thereof. Among these, high pressure method low density polyethylene, linear low density polyethylene (so-called LLDPE), high density polyethylene, polypropylene, polypropylene random copolymer, polyethylene terephthalate, polyamide and the like are preferable.

  When a nonwoven fabric made of crimped fibers is used as another spunbond nonwoven fabric laminated with the nonwoven fabric of the present invention, the resulting laminate is excellent in flexibility, bulkiness, and touch. Moreover, when the thing which extended | stretched the nonwoven fabric which consists of a mixed fiber of each thermoplastic resin and a thermoplastic elastomer is used, in addition to the said characteristic, the laminated body obtained is excellent in a stretching property.

When the nonwoven fabric of the present invention is used for an absorbent article, for example, a disposable diaper top sheet, a second sheet, or a sheet (core wrap) that wraps an absorbent body, the fineness is 0.5 to 3 denier and the basis weight is 7 to 50 g / m ^2. It is preferable to set it as the range.

  Moreover, when using the nonwoven fabric of this invention for the sheet | seat (core wrap) which wraps the absorber of an absorbent article, you may laminate | stack with the said melt blown nonwoven fabric.

  The film laminated with the nonwoven fabric of the present invention is preferably a breathable (moisture permeable) film so that the rash reduction effect that is a feature of the nonwoven fabric of the present invention can be utilized. Examples of such a breathable film include various known breathable films, for example, films made of thermoplastic elastomers such as moisture-permeable polyurethane elastomers, polyester elastomers, polyamide elastomers, and thermoplastic resins containing inorganic or organic fine particles. Examples thereof include a porous film formed by stretching a film to be porous. The thermoplastic resin used for the porous film is preferably a polyolefin such as high-pressure method low-density polyethylene, linear low-density polyethylene (so-called LLDPE), high-density polyethylene, polypropylene, polypropylene random copolymer, or a composition thereof.

  The non-woven fabric of the present invention may be used after being subjected to secondary processing such as gear processing, printing, coating, laminating, heat treatment, and shaping, as long as the object of the present invention is not impaired.

<Nonwoven Fabric Manufacturing Method>
When short fibers are used as the raw material for the nonwoven fabric, they can be produced by various known production methods, for example, a wet method or a dry method (card).

<Method for producing long-fiber nonwoven fabric>
The long-fiber nonwoven fabric of the present invention can be produced by various known methods for producing nonwoven fabrics, but the method produced by the spunbond method is preferred in terms of excellent productivity.

  When producing the long-fiber nonwoven fabric of the present invention by the spunbond method, when producing a spunbond nonwoven fabric comprising single fibers of the olefin polymer composition, 180 to 250 ° C, preferably 190 to 230, with one extruder. From 0.4 to 1.5 g / min, preferably 0.5 to 0.8 g / min from a spinneret melted at ℃ and having a spinning nozzle set at 180 to 250 ° C., preferably 190 to 230 ° C. The fiber is spun by discharging with a hole discharge amount, and the spun fiber is cooled by cooling air at 10 to 40 ° C., preferably 20 to 40 ° C., and 2000 to 7000 m / min, preferably 3000 to 6000 m / min. After pulling the fiber with high-speed air for a minute to a predetermined fineness, collecting it on a collection belt and depositing it on a predetermined thickness (weight), needle punch, water jet, supersonic sound The method using means of equal or may be prepared by entangling by entangling method and a method of thermal fusion portion by using a heat embossing or hot air-through using an embossing roll.

<Absorbent article>
The absorbent article of the present invention is an absorbent article formed by using the nonwoven fabric, preferably a long fiber nonwoven fabric, as a top sheet and / or a second sheet, or a sheet (core wrap) that wraps an absorbent body. The absorbent article of the present invention includes disposable diapers, pants or sanitary products, urine collection pads, pet sheets and the like.

  In particular, when using a disposable diaper top sheet, a second sheet or a sheet (core wrap) that wraps the absorbent body, when using a nonwoven fabric made of fibers of an olefin polymer composition, 100 parts by weight of the olefin polymer, 0.5-30 parts by weight of an anionic surfactant in acid form, or 0.5-30 parts by weight of an anionic surfactant in acid form, and 0.5-30 parts by weight of a nonionic surfactant It is preferable.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

  In addition, the following methods evaluated the degree of the rash suppression effect in an Example and a comparative example.

[Rash evaluation method]
The degree of rash was evaluated by the following procedure.

  Dilute feces collected from a healthy 3-year-old child (male) to 1% with distilled water, and collect the supernatant obtained by centrifugation at 3000 rpm for 15 minutes using a cooling high-speed centrifuge H-201FR manufactured by Kokusan Co., Ltd. And used as an evaluation solution. After immersing the nonwoven fabric samples produced in the following Examples and Comparative Examples for 1 minute and 30 minutes in this evaluation solution, the rabbit 3 was prepared based on ISO 10993-10 (test for inflammation and delayed hypersensitivity). It was affixed to the skin of a mouse and the state of the skin 48 hours later was observed.

〔Evaluation criteria〕
1 point: All three animals had almost no change in skin condition.

      2 points: Slight edema and spots appeared in 1 to 2 animals.

      3 points: Slight edema and spots appeared in all 3 animals.

      4 points: Edema and spots appeared in 1 to 2 animals.

      5 points: Edema and spots appeared in all 3 animals.

      6 points: All three animals showed marked edema and spots.

[Extrudability]
1 point: Good biting into the extruder screw.

      2 points: Difficult to bite into the extruder screw. There is nozzle pressure fluctuation.

[Example 1]
A composition containing an anionic surfactant in acid form or a nonionic surfactant in an amount shown in Table 1 with respect to 100 parts by weight of the olefin polymer was prepared as follows. 10 parts by weight of stearic acid (trade name Lunac S-90V, manufactured by Kao Corporation) as an anionic surfactant in acid form, and ethylene oxide adduct of stearyl alcohol (BASF (former Ciba)) as a nonionic surfactant , Irgasurf HL560), melting point (Tm): 142 ° C., MFR: 60 g / 10 min propylene / ethylene random copolymer (PP-1): 79.95 parts by weight, antioxidant (BASF ( A product name Irgafos 168) manufactured by the former Ciba company) was melt-kneaded at 230 ° C. together with 0.05 parts by weight and extruded to prepare a pellet-like masterbatch (MB-1).

  Subsequently, 40 parts by weight of the MB-1 was added to 60 parts by weight of PP-1 and mixed to obtain a propylene polymer composition (Composition-1).

  In order to evaluate the extrusion performance, the composition-1 was put into a single screw extruder (screw diameter 30 mm, L / D = 30) and melted by heating at an extrusion rate of 4.4 kg / hr and a resin temperature of 200 ° C. As a result, the biting state of Composition-1 into the extruder screw was as good as when no surfactant was added.

Subsequently, the composition-1 was melt-spun by a spunbond method to obtain a long fiber nonwoven fabric. Following spinning, the embossing roll has a rhombus shape, an embossing area ratio of 18%, and an embossing area (area per imprinting) of 0.41 mm ^2. Heat embossing was performed at a pressure of 60 N / mm to obtain a long fiber nonwoven fabric having a basis weight of 20 g / m ² . Using the obtained long-fiber nonwoven fabric, the degree of rash was evaluated by the above-described rash evaluation method. The results are shown in Table 1.

[Examples 2 to 6]
As the anionic surfactant in the acid form and the nonionic surfactant, the following compounds were used, and the same procedure was performed as in Example 1 except that the addition amount was changed as shown in Table 1. Obtained. Using the obtained long-fiber nonwoven fabric, the degree of rash was evaluated by the above-described rash evaluation method. The results are shown in Table 1.

Myristic acid (C14): trade name, Lunac MY-98, manufactured by Kao Corporation
Ores-4-phosphate (C18): Toho Chemical Industries, Ltd. Product name Phosphanol RB-410
[Example 7]
A composition containing an anionic surfactant in acid form or a nonionic surfactant in an amount shown in Table 1 with respect to 100 parts by weight of the olefin polymer was prepared as follows. 5 parts by weight of dodecyl phosphate (manufactured by Takemoto Yushi Co., Ltd.) as an anionic surfactant in acid form, and 14 parts by weight of poly (oxyethylene) 1,6-hexanediol dilaurate (manufactured by Takemoto Yushi Co., Ltd.) as a nonionic surfactant 1 part by weight of poly (oxyethylene) sorbitan trioleate (manufactured by Takemoto Yushi Co., Ltd.), propylene / ethylene random copolymer (PP-1) having a melting point (Tm): 142 ° C. and MFR: 60 g / 10 min: 79.95 parts by weight, antioxidant (manufactured by BASF (former Ciba), trade name Irganox 1010) was melt kneaded at 180 ° C. together with 0.05 parts by weight, and extruded into a master batch (MB-2). Prepared.

  Next, 20 parts by weight of MB-2 was added to 80 parts by weight of PP-1 and mixed to obtain a propylene polymer composition (Composition-2).

  In order to evaluate the extrusion performance, composition-2 was put into a single screw extruder (screw diameter 30 mm, L / D = 30), and melted by heating at an extrusion rate of 4.4 kg / hr and a resin temperature of 200 ° C. As a result, the biting state of Composition-2 into the extruder screw was as good as when no surfactant was added.

Subsequently, the composition-2 was melt-spun by a spunbond method to obtain a long fiber nonwoven fabric. Following spinning, the embossing roll has a rhombus shape, an embossing area ratio of 18%, and an embossing area (area per imprinting) of 0.41 mm ^2. Heat embossing was performed at a pressure of 60 N / mm to obtain a long fiber nonwoven fabric having a basis weight of 20 g / m ² . Using the obtained long-fiber nonwoven fabric, the degree of rash was evaluated by the above-described rash evaluation method. The results are shown in Table 1.

[Examples 8 and 9]
Similar to Example 7 except that the nonionic surfactant used in Example 7 was used, the following compound was used as the anionic surfactant in the acid form, and the addition amount was changed as shown in Table 1. The long fiber nonwoven fabric was obtained. Using the obtained long-fiber nonwoven fabric, the degree of rash was evaluated by the above-described rash evaluation method. The results are shown in Table 1.

Anionic surfactant Octyl phosphoric acid (C8): Takemoto Yushi Co., Ltd. Octadecan-1-yl dihydrogen = phosphate (C18): Takemoto Yushi Co., Ltd. Hydrogen dioctadecyl phosphate (C18): Takemoto Yushi Co., Ltd.

[Comparative Example 1]
A long fiber nonwoven fabric was obtained in the same manner as in Example 1 except that only the nonionic surfactant used in Example 1 was added and no anionic surfactant in acid form was added. Using the obtained long-fiber nonwoven fabric, the degree of rash was evaluated by the above-described rash evaluation method. The results are shown in Table 2.

[Comparative Examples 2 to 6]
PP-1 was melt-spun by a spunbond method to obtain a long fiber nonwoven fabric. Following spinning, the embossing roll has a rhombus shape, an embossing area ratio of 18%, and an embossing area (area per imprinting) of 0.41 mm ^2. Thermal embossing was performed at a pressure of 60 N / mm to obtain a long fiber nonwoven fabric (NW-1) having a basis weight of 20 g / m ² . On the other hand, as Comparative Examples 2 to 6 shown in Table 2, the following compounds were dissolved in an isopropyl alcohol aqueous solution adjusted to a concentration at which each can be dissolved to obtain a coating solution, which was applied to NW-1, and then dried. Let Coating and drying were repeated, and the weight after drying was adjusted to a predetermined addition amount shown in Table 2. Using the obtained nonwoven fabric, the degree of rash was evaluated by the rash evaluation method described above. The results are shown in Table 2.

Anionic surfactant Citric acid (C6): Reagent manufactured by Wako Pure Chemical Industries, Ltd. Octyl acid (C8): Reagent manufactured by Kyowa Hakko Chemical Co., Ltd. Stearyl alcohol (C18): manufactured by Kao Corporation Product name Calcoal 8098
Dodecyl phosphoric acid (C12): Nonionic surfactant poly (oxyethylene) 1,6-hexanediol dilaurate manufactured by Takemoto Yushi Co., Ltd. Poly (oxyethylene) sorbitan trioleate (manufactured by Takemoto Yushi Co., Ltd.)

  The fiber of this invention and the nonwoven fabric containing the said fiber can be used conveniently as a top sheet of sanitary materials, such as a paper diaper and sanitary goods, or a second sheet.

Claims (6)

An anion in the form of an acid which is a fatty acid having 9 or more carbon atoms with respect to 100 parts by weight of a propylene / α-olefin random copolymer composed of propylene having a melting point (Tm) of 125 to 155 ° C. and an α-olefin. A fiber comprising an olefin polymer composition containing 0.1 to 30 parts by weight of a surfactant, wherein the anionic surfactant in the acid form, which is a fatty acid having 9 or more carbon atoms, is melt mixed into the fiber. Refined fiber.   The fiber according to claim 1, wherein the olefin polymer composition contains 0.1 to 30 parts by weight of a nonionic surfactant. The fiber according to claim 1 or 2 , wherein the fiber is a long fiber. A nonwoven fabric comprising the fiber according to claim 3 . The absorbent article which uses the nonwoven fabric of Claim 4 for a top sheet and / or a second sheet. The absorbent article which uses the nonwoven fabric of Claim 4 for the sheet | seat which wraps an absorber.